Even if they use a live CD with rainbow tables, you can be safe if you use both cases, numbers, and symbols in a long password. Don't use words or anything; I like coming up with a favorite quote, getting the first letters and sprinking in numbers, symbols, and case changes. It's easy to remember but impossible to guess.

If you're not using the computer while they're over, take the power plug off of the PSU. Or unplug the PSU from the motherboard and use a little padlock on the side of the case (most cases have a little hole for one) or the chassis intrusion alarm if your mobo/case has one.

1. Buy a cheap replacement keyboard
2. Apply a thin layer of super glue to the surface of some of the main keys. (it will stay wet for hours unless you apply pressure.
3. Find out which one of your "friends" has the keys to your cheap keyboard glued to his fingers.

1. Buy a cheap replacement keyboard
2. Apply a thin layer of super glue to the surface of some of the main keys. (it will stay wet for hours unless you apply pressure.
3. Find out which one of your "friends" has the keys to your cheap keyboard glued to his fingers.

1. Buy a cheap replacement keyboard
2. Apply a thin layer of super glue to the surface of some of the main keys. (it will stay wet for hours unless you apply pressure.
3. Find out which one of your "friends" has the keys to your cheap keyboard glued to his fingers.